RangeRovers.net Forum banner

1 - 20 of 20 Posts

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #1 (Edited by Moderator)
Hello All,

Does anyone know how to repair or a place that repairs the main amp XQK100340 H70858? Any help or leads greatly apprecited.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,420 Posts
Assuming these are both Hi Line systems, and you ever find someone who can fix the HK amp...Let us know!
There are a few folks on here that are threatening to fix them, but so far, no go....
The DSP amps have become unicorn poop.
Marty has a good replacement using the door amps from earlier systems and some tricky wiring mods.....
I will be purchasing one of his systems soon for the white 02 ($100 British Pounds).......And probably one for the Borrego when it's DSP augers in!
I can't see buying a 3rd DSP since they seem to die of old age more than any other power electronics I have ever operated!
Thanks for the option, Marty:thumb:

If anyone want's a couple of dead DSPs to play with, let me know...I have them here in Hawaii, but I will not be here long.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #3
Thanks for the response mate. I figured fixing these was a long shot but I thought I give it a try. I might just have to buy a used one and be done with it. I am also looking to repair the part that goes inside the subwoofer box (not sure if it's another Amp or a module), one that is made of aluminum. Do you know if anyone fixes these?
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,420 Posts
Someday, somewhere, someone will tackle the problem.
In the meantime, we have Marty's solution, if you want to keep the factory look and great sound.
The Sub woofer amp is probably ok, as these seem to be pretty robust.
If you can find a tested working used DSP amp for less than 200 bucks, then that is easy.
Marty's module is pretty close to a drop in, and would probably outlast another DSP amp.
As I mentioned, from personal experience, these seem to have a self destruct by date inside!
Good luck!
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #5
Cheers mate. I will buy a used Amp and see if the subwoofer works. Thanks for the advise.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
764 Posts
I’m lucky, mine is still going strong, but it wasn’t when I bought the car, I got the only one advertised, cost £300.
but I suppose as there so rare these days it wasn’t bad, I’m swapping it out for a more upto date system pretty soon.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #7
I like to keep mine OEM so I will just look for a used one. I don't understand why there is no one taking a shot at repairing these (including the Subwoofer Amp).
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
233 Posts
The problem with the DSP amplifiers isn't that no one has looked - they have. The failure appears to be in one of the custom ICs on the boards, and without a source of those - you're pretty much out of luck.

Buying a used one is a lot of money for something that can fail at any moment. The better option is to go Marty's route and replace with a set of the door amplifiers, and run a couple of additional wires back to the amplifier location to feed the amps for the rear doors.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #9
Thanks for the response and advice mate. Have not looked at Marty's solutions. I just may have to take a look. Cheers.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
230 Posts
Maybe I'm being Nigel Naive here but I do wonder how hard it would be to adapt a more readily available DSP amplifier system to work with the P38 controls and head unit. After all a DSP amplifier is basically just a digitising chip / chipset which turns the audio stream into digital data that can then be sliced up, modified, tweaked or whatever by the internal programming and control inputs to drive bunch of class D amplifiers. One amplifier per speaker. Class D amps are about as simple as audio gets and, from the manufacturers point of view, all the hardware is essentially the same. Just supply the right number of amplifiers and speaker connections, slice the audio to match and program the input side to match the car controls. Then charge eight times what its really worth! Simples.

Obviously something along these lines is quite practical. For example Alpine do the PDP-E800DSP an 8 channel system that you set up using a computer air phone / tablet app see https://www.alpine.co.uk/p/Products/SingleView/PDP-E800DSP . Allegedly able to fit "anything" (sort of). Price is no doubt eye-watering but that was just the first thing that came up on a search. No doubt a bit of digging through alibaba et al would find similar for much, much less.

Repurposing from another vehicle basically requires the right number and type of audio inputs and speaker outputs. Ought to be easy enough to do a control adapter module with one of the inexpensive hobby computer boards Raspberry PI, Arduino or whatever as these seem to have plenty of provision for real world inputs. Can't see that cracking the codes would be that difficult.

Clive
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #11
Thanks for the info mate. But to be honest, I just don't have the time to tackle this issue (seems like likes of work/time) with the other issues that P38's (I have 2) have to keep them running. Maybe someday someone may tackle fixing the OEM DSP's. In the meantime, I will just dish out the money for another DSP and be done with it. Cheers again.
 

·
LEGACY VENDOR
1995-2002 Range Rover P38A
Joined
·
4,174 Posts
I have looked fairly extensively into the original DSP amplifier to try and find what fails, and why, and see if it is repairable.

I've got about 5 amps here which are all dead, and one which actually still works.

So far what I have found out is that when they fail completely, it appears that the amplifier chips are being held in standby mode and not switching on. I traced the circuitry back to what controlled this and tried replacing a couple of parts, with no success. I even tried bypassing this to force the amp chips into waking up - but even then there was still no audio being processed and coming out.

I've looked into the input circuitry that's used to wake up the DSP chips that do all the work, and that appears to be working as designed. The power supply sections also all seem to be working properly - nothing abnormal when you go to power it up and make it do some work, so no 'under load' faults that I can see.

I have also tried swapping over some of the EEPROM and RAM chips between boards to see if it's something simple like faulty memory that's causing the DSP chip to flag an error when starting up - but again, nothing different.

After everything I have ruled out, it indeed appears to be a fault in at least one of the actual DSP processing chips itself - which are covered in a blob of epoxy on the board. I did try to remove this on one of the faulty boards I had, in case I could get to the chip and find out what it was - but my attempt ended up physically damaging the DSP chip. So unfortunately it appears that once these units have failed, then it's totally dead.

I have also looked into other options, such as swapping in an amp from another vehicle - though the DSP settings on the P38 are somewhat limited - there MAY be a version of a DSP amp from a BMW of around the same era that might work. Some people put the XQK100210 amp from a Disco II in, but this isn't a DSP unit and only some of the speakers work. I looked briefly into whether you could do some rewiring/swapping of pins about to get it to work like a bog standard 8 channel amp (low and mid/high for each door) but the way that the system is set up in the D2 appears to have more low end speakers in it, so then you're into trying to mess about with the components on the board to get the correct audio signals to the proper speakers. That ended up in the too hard basket - which is why I developed the replacement for the DSP amp which has 4x standard P38 door amps on it, and a custom wiring loom which wires into the vehicle wiring, and additional feeds to run to the radio head unit for the inputs for the rear left/right doors. This can also be then used with aftermarket head units with either line balancing transformers on each input, or an attenuator circuit for each input depending on if you are using line level output or amplified output from the replacement head unit.

I haven't had time recently to devote to doing any more with DSP amps or looking into other options, so at the moment I'm still going with the theory that they are unrepairable I'm afraid!

Marty
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Discussion Starter #13
Hey Marty,

Thank you so much the the deailed information you provided. I gotten the sense that fixing these (if possible) takes a lot of time and technical know how. I for one don't have the time to devote to this. Therefore I will just try to buy a used DSP and be done with it. When I posted this thread I was just curious if anyone had fix them, how simple or hard it was, or if there was someone out here willing to fix them for a cost. But it looks like none of these are currently possible. Again, I appreciate your response and great info. -Alexander
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,420 Posts
Aloha Marty,
Thanks for posting the troubleshooting you have done on the DSP's.
The final step rang a loud bell here as I have had some in depth conversations with some top end industrial and Military power electronics engineers in relation to the encapsulation of Solar power equipment.
The issue with rigid encapsulation, like the "Blob of Epoxy" that HK used on these amps is the different expansion rates of the electronics and the epoxy. This causes the surface mount components to eventually shear off of the board. A lot of epoxy compounds will also shrink a bit with age so even though unused, the amps will fail "on the shelf" in some cases....
When you mentioned this blob I realized this is most likely the culprit as I have now experienced the total failure of 3 amps. they all seem to go out in the same way. Sudden onset of issues, and total failure soon thereafter. The one in the Borrego goes very "Crackly" in very hot weather after constant use (Think I-5 through the Central Valley, Calif on a summer day) So far, it has recovered after cooling off. I have checked all accessible connectors, and found no corrosion. What is left therefore is the amp......It is still working (Touch wood!)
Since I am shipping my white 02 to Calif, and will be driving it more, I do want to have all the speakers working. (I have the Disco amp which only works the fronts and no sub currently)
I will send you an e mail for details on how to get one of your replacements.

Edit: Called one of the aforementioned engineers, he may have solvents available to dissolve the rigid epoxy commonly used for this application....I may send him the 2 dead DSPs I have here and see what kind of nasty chemicals he can use on them?
 

·
LEGACY VENDOR
1995-2002 Range Rover P38A
Joined
·
4,174 Posts
Hmmmmmmmmm that sounds rather intriguing... I might look into that aswell and see if there's a way of removing the epoxy in a non-destructive manor which doesn't damage the chip... I have SMD soldering tools here, so if I can remove the epoxy and get the chips off the board then maybe re-soldering them will be enough to get it working again...

I hadn't thought about the heat thing being an issue - but thinking about it more, the DSP chips have their own heatsinks on the opposite side of the board, so they must get fairly warm when they're working...

On my website there's an link so that you can drop me a message about the DSP replacement boards if you want.

Cheers,
Marty
 

·
Registered
Joined
·
5 Posts
Hi, apologies for raising an old thread. My Amp has died and just waiting for it to come back from the repairers. Looking at having a dig into the offending resin problem when it comes back. Did anyone ever give it a real try since the last post.
Cheers
 

·
Super Moderator
Joined
·
1,917 Posts
My Amp has died and just waiting for it to come back from the repairers.
Where have you sent it and do they reckon they can fix it? If they can, at a reasonable cost, then there may be a lot of work out there for them.....
 

·
Registered
Joined
·
5 Posts
I sent it to "retrocaraudio". Before I read any of the threads here. But came back with DSP ######! as I gather everyone else has.
 

·
Registered
Joined
·
174 Posts
Edit: Called one of the aforementioned engineers, he may have solvents available to dissolve the rigid epoxy commonly used for this application....I may send him the 2 dead DSPs I have here and see what kind of nasty chemicals he can use on them?
Did your engineers come back to you with an efficient way of dissolving the epoxy on these? Mine has died and I'm curious. Finding a replacement for the 17 speaker system is a nightmare.

Thanks,

David.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,420 Posts
Did your engineers come back to you with an efficient way of dissolving the epoxy on these? Mine has died and I'm curious. Finding a replacement for the 17 speaker system is a nightmare.

Thanks,

David.
Aloha David,
Sorry to report that being electrical Engineers, and darned good ones at that, they are virtually
useless on practical stuff, and promptly lost the board I sent them......
In the meantime, I bought 3 amps from wrecks and got 2 that work! $75 bucks out for 2 good ones is a deal, says I!

I would contact Marty for his solution as it will keep the look and great sound of the factory set up.
Good luck!
 
1 - 20 of 20 Posts
Top